import java.util.LinkedList;
import java.util.Queue;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 26727
 * Date: 2024-09-26
 * Time: 10:41
 */
class Solution9 {
    int m,n,count;
    int[] dx = {1,-1,0,0};
    int[] dy = {0,0,1,-1};
    boolean[][] visit;
    public int maxAreaOfIsland(int[][] grid) {
        m = grid.length;
        n = grid[0].length;
        visit = new boolean[m][n];

        int ret = 0;
        for(int i = 0; i < m; i++) {
            for(int j = 0; j < n; j++) {
                if(grid[i][j] == 1 && !visit[i][j]) {
                    count = 0;
                    bfs(grid,i,j);
                    ret = Math.max(ret,count);
                }
            }
        }
        return ret;
    }

    void bfs(int[][] grid,int i,int j) {
        Queue<int[]> q = new LinkedList<>();
        q.add(new int[]{i,j});

        count++;
        visit[i][j] = true;

        while(!q.isEmpty()) {
            int[] t = q.poll();
            int a = t[0],b = t[1];

            for(int k = 0; k < 4; k++) {
                int x = i+dx[k],y = j+dy[k];
                if(x >= 0 && x < m && y >= 0 && y < n && grid[x][y] == 1 && !visit[x][y]) {
                    bfs(grid,x,y);
                }
            }
        }

    }
}
